252 HAK0AL OF GATTLE-FEEDIKG. 



In Xo. 1 and No. 2, whose crude fibre was easily digest- 

 ible, the actual amount of non-nitrogenous nutrients di- 

 gested was greater than that calculated ; in No. 8 the two 

 were nearly equal ; in No. 4, where the crude fibre was 

 less digestible^ it was only 88.5 per cent, of the theoretical 

 amount. 



It is obvious, from such results as these, that while the 

 compensation between digested crude fibre and undigested 

 nitrogen-free extract may be an aid in f onning an estimate 

 of the digestibility of a fodder, it is not sufficiently close 

 to serve as the basis of exact calculations. 



Recent experiments on the horse, to which reference 

 will be made in subsequent pages, have shown that crude 

 fibre is less digestible by this animal than by ruminants, 

 and that consequently this compensation only takes place 

 ill very young and tender fodder. 



Composition of Digestible Portion of Nitrogen-free 

 Extract. — It has been shown, by essentially the same 

 method as that applied to crude fibre, that the digestible 

 portion of the nitrogen-free extract has very nearly the 

 composition of starch. 



We tnay therefore assume that all the digestible non-ni- 

 trogenous substances of the fodder, with the exception of 

 the fat, are, like starch itself, converted into sugar or sugar- 

 like substances, and as such are resorbed and taken into 

 the circulation. 



Further exceptions to this rule are the small quantities 

 of organic acids either contained ready formed in the fod- 

 der or pi'oduced during digestion from the carbhydrates. 



The quantity of these, however, is very small, and we 

 can,"^ in genei*al, regard all the digestible non-nitrogenous 



* With the reservations made on p. 184. 



